Following the advent of multichannel audio, a five-channel audio technology has been recently proposed that attempts to reproduce some or most of the auditory experience of an acoustic performance in its original venue, as described in U.S. Pat. No. 6,845,163, and Johnston J. D. and Lam Y. H., “Perceptual Soundfield Reconstruction”, 109th AES Convention, paper No. 5202, September 2000. The audio scheme uses a specially constructed seven-channel microphone array to capture cues needed for reproduction of the original perceptual soundfield in a five-channel stereo system. The microphone array consists of five microphones in the horizontal plane, as shown in FIG. 1, placed at the vertices of a pentagon, and two additional microphones laying in the vertical line in the center of the pentagon, one pointing up the other down.
The seven audio signals captured by the microphone array are mixed down to five reproduction channels, front-left (FL), frontcenter (FC), front-right (FR), rear-left (RL), and rear-right (RR), as shown in FIG. 2. Listening tests demonstrated significant increase of the “sweet spot” area of the new scheme compared to the standard two-channel audio in terms of sound-source localization.
It is also known in the field of multi-channel audio to reproduce a signal split into its separate “direct” and “diffuse” components, the direct components being those components received directly at a listener from a sound source plus several early reflections, the diffuse components then being the following components, which will typically be the reverberant components. Such a scheme is described in Rosen G. L and Johnston J. D. “Automatic Speaker Directivity Control For Soundfield Reconstruction”, presented at the 19th AES International Conference, Schloss Elmau, Germany, 21-24 Jun. 2001. In this paper it is described how the direct components may be reproduced by a first speaker, and the diffuse components reproduced by a second speaker using a diffuser panel.